G&L L-2500 action

I love the sound of my G&L L-2500 1998. But I want to lower the action. I can't do it by using the trussrod or adjusting the bridge. It have a medium action right now. I'm using La Bella Super Steps (.50 .70 .85 .110 .128). I don't want to change the neck.

Jose, lighter strings won't help - the bottom edge of the string will still be the same distance from the fretboard. If the difference is very small, exposed core strings may do the trick.

Exposed core strings (some manufacturers have diff. names for them) are those that have only the main, core string going over the bridge saddle. Windings start beyond that point. The net effect of this is that the bottom edge of the string is closer to the fretboard. If that doesn't do it, it's back to the shim.

Shim could be a thin wood 'wedge' under the bridge side of the neck pocket, or maybe a very thin metal strip. What you want to do is to 'raise' the bridge side of the neck, thus allowing the bridge saddles to do their work in adjusting the action. Wish I could draw it - it's much simpler than it sounds.

lighter strings have less tension thus the neck will not bow as much as it is now and the strings will be closer to the frets.

btw, the G&L I had had a 3 bolt neck and this one, like the 70's fenders, has a little allen screw which you can adjust the neck angle with.

Jose, if you have the 3 bolts neck, keep in mind you have to loosen the three bolts a bit before you can adjust the small allen, I'll send it to a tech though because improper adjustments could throw the whole instrument out of intonation.

when I prees the notes after the 12 fret, the rest of the note are pretty close to the fretboard ( I need to use light touch).
I need to straight the neck. This neck has a bow near the 9 to 12 fret and the trussrod was adjusted all the way.

A shim is not going to change the string tension. Lighter strings will effect the neck relief slightly. Changing from through body to top load will make even less of a difference.

Shiming the neck changes the angle of the neck in the neck pocket. Therefore, it changes the angle of the neck in relation to the body.

To shim, I suggest thin wood veneer.

Remove the neck. Cut a piece of veneer to cover the back half of the neck pocket. You'll have to drill holes through it for the bolts. Replace the neck. You have now tilted the neck downward and while you haven't straighten the neck, you have changed the nut's relative position to the bridge which should improve your action.

Although you will still have a bow in the neck and the action will not be fluid throughout the whole board.

Before you do any of this, I suggest removing the strings completely and allowing the bass to sit for a week or so, then attempt to further tighten the rod. I would be very surprised if the truss is really bottomed out and the neck is still that bowed. If it is, G&L may have some warrenty obligations.